|Avalanche path||A terrain feature in which an avalanche occurs, this is normally split into the start zone, track and runout zone|
|Avalanche terrain||Any terrain which has the potential to form or be part of a snow avalanche|
|Bonding||Refers to a snowpack which has undergone some metamorphism and has many links between the individual snow grains, generally leading to a stronger “bonded” snowpack.|
|Cornice||An overhanging mass of wind sculpted snow projecting beyond the crest of a ridge|
|Crust||A hard surface layer which can be formed by solar radiation, wind or rain which has the potential to cause instability when buried.|
|Destructive Scale of Avalanches||D1:Too small to bury or injure a person. Typical mass: less than 10 tons.
D2:Could bury, injure or kill a person. Typical mass: 100 tons.
D3:Could bury or destroy a car or destroy a small building. Typical mass: 1000 tons.
D4:Could destroy a railway car, several buildings, or a forest up to 10 acres. Typical mass: 10,000 tons.
D5:Could destroy a village or forest of 100 acres or more; the largest known avalanches. Typical mass: 100,000 tons.
|Freezing level||The elevation at which the air temperature is at 0° Celsius|
|Half (1/2)||Used with compass directions, e.g. “lee to the easterly half” refers to the aspects facing west from north through to south.|
|Instability||A weakness or lack of stability indicating that additional loads will result in a given probability of avalanche occurrence.|
|Lee (leeward)||The side of a mountain protected from the wind|
|Loose snow||A type of avalanche which originates at a point and spreads out as it descends.|
|Melt-freeze||A metamorphic process when snow changes from a solid to a liquid and back again and may result in the formation of a crust.|
|Pockets||Small isolated terrain features|
|Quarter (1/4)||Used with compass directions, e.g. “lee to the easterly quarter” refers to the aspects facing northwest through to southwest.|
|Runout zone||The area at the bottom of an avalanche path where an avalanche starts to decelerate and comes to rest, this is where the debris is located after an avalanche has occurred.|
|Safe travel technique||The use of appropriate terrain to move given the posted danger scale (e.g. stay to ridges and well away from runout zones, or slopes less than 30°)|
|Shady aspect||The side of a mountain protected from the sun|
|Slab||A cohesive layer of snow|
|Sliding hazard||A hazard posed by very hard or icy conditions, also known as ‘slide for life conditions’.|
|Solar aspect||The side of a mountain exposed to the sun|
|Start zone||The area at the top of an avalanche path in which unstable snow may fail. Most commonly has an angle greater than 250.|
|Terrain traps||Terrain features which in the event of an avalanche would compound the effect (e.g. gullies, small bowls)|
|Track||The area which connects the start zone and runout zone, this can be either confined or unconfined.|
|Unsupported slope||Slopes which are not being supported by the terrain, e.g convex rolls|
|Weak layer||A layer in the snowpack identified as a possible failure plane|
|Wet snow||Snow with a water content greater than 3% and has a temperature of 0° Celsius|
|Whumphing||The sounds associated with the rapid settlement or collapse of a snowpack, when weighted.|
|Wind loading||The transport of snow by the wind causing an additional build up of snow on a lee slope|
|Wind slab||A cohesive layer of snow caused by wind loading|
|Windward||The side of a mountain exposed to a wind|